Thank you for the great responses
I've just arrived in France after a terrible drive that started last night (shortly after posting) and included a ferry delay, a blowout (car tyre), and several accidents that slowed down traffic (due to the high winds).
I realise things are unlikely to be 'plane sailing' with an aircraft, but a 9 hour drive is proving exhausting.
Early this morning I picked up the new pilot magazine that features two articles on the subject of buying cheap. One by a seemingly objective reported, the other by the guy that owns/runs 'just plane trading'. Both articles were very informative, as were the comments I've received from you all.
I think, to summarise, it's going to be a gamble. I could end up lucky and buy an older plane that will run and run with little expensive problems on an airframe with high hours, and an engine 'on condition' or if I'm lucky, with some hours left in her. Or, I get unlucky, pay my 20k and throw 150% of that at it in the first year, followed by my entire budget for the next few years until I get bored (or more likely the wife puts her foot down) and sell it for a fraction of the cost.
It seems I can hedge my bets by following some 'buyers rules' and take an engineer with me, but he may not see everything without a strip down, so I could still get burned...
Hmm.
I realise now that whatever the practicality of me using this to solve my commuting problem, I'll probably end up buying something. I clearly need to become much more well informed on the subject, then I'll roll the dice.
I was interested to hear about the person who suggested a 2 seater would make for a not entirely uncomfortable ride, and the several comments that seemed hopeful that such an undertaking could/should be possible. - I'd like to reference usernames, but I didn't note them before hitting reply.
I've been following the price of planes for the last year or so and I've noticed cheaper ones coming available of late, but I didn't know if they were rust buckets or real flyers. Currently just plane trading have a piper pa22-135 (from 1954!!!) for 15k, with a TT of 3033 and engine hours at 767. Last month they had a piper pa28-190 (1967) TT 10620, eng 1880. These adverts baffle me, as they seem great value, but I worry about my naivety.
I'm going to look to buy in 3-4 months, which will give me a little more time to get up to speed and to watch the Market. I'll also do some serious thinking about exactly what I'll want to do with it on a weekly basis, in addition to my aspirations of using it to get home.
In the mean time, I'd appreciate any advice I can get from you all.
Here's a bit more about me, to answer some earlier questions:
I'm a very keen golfer - so trips to Scotland play a regular role in my spare time;
I'm a management consultant (okay, I can hear you all hissing.), so I can be flexible about working hours;
I would love to take my wife and two of my (small/young) children away for short trips, if space/experience/comfort permit;
I intend to do 90% of my flying alone;
I hope to do instruments and night quals immediately after my ppl;
My purchase budget of approximate. 20k is fixed, and my annual budget of an absolute max of 20k is fixed (although I hope this isn't entirely required);
I am in my late 30s (in case you're wondering);
My eldest son is 14 and has started lessons in France. He hopes to be a commercial pilot one day, so I would love for him to be able to share the plane with me once he gets to 17(assuming he passes his ppl);
I am based in Sheffield, but work anywhere between London and Yorkshire/midlands; and,
My home is in Normandy (near mont SM).
That's about all there is to know.
Again, I'm incredibly grateful for the comments posted so far, both sobering and encouraging, and I hope you're enclined to post more.
Now for 18 hours with the family before I have to leave again!